Navigating Nutritional Psychiatry in Eating Disorder Treatment: A Dietitian’s Perspective

Something I was constantly reminded of in graduate school is that nutrition is a young science. When we call a field “young,” we’re acknowledging that it changes quickly as our population evolves and our understanding of the human body deepens. Some concepts, like the importance of fiber, have been well-established for decades. Others, like the impact of microplastics, seed oils, nutrient depletion in soil, or nutritional genomics, are still emerging. As an eating disorder dietitian, I’m especially interested in any research that may influence how I can best support my clients. Over the last few years, the concept of “nutritional psychiatry” has gained traction. While it’s an intriguing area of study, its application in eating disorder treatment requires nuance and caution.

According to the Eating Recovery Center, nutritional psychiatry examines “how the food we eat — and the bacteria in our gut — affects our mental health. It focuses on how nutrients support brain function, help regulate mood, and reduce stress in the body” (ERC, 2025). This framework explores mechanisms like the gut–brain axis, microbiome diversity, chronic inflammation, neurotransmitter precursors, and even epigenetics. Research in the general population has shown correlations between dietary patterns like Mediterranean-style eating and lower rates of depression. Early intervention trials suggest that dietary changes may support mood for some individuals. While the evidence is still young, the interest is growing, and the field is exploring the possibility that nutrition may play a complementary role in mental health care. For many people, learning why food matters for mental health can actually feel empowering and validating when it’s approached with enough food, flexibility, and care.

Like many emerging areas of research, nutritional psychiatry has limitations. Much of the evidence is correlational, making it hard to determine whether dietary patterns influence mood or whether people struggling with mental health simply eat foods that require less effort to prepare and are often lower in the nutrients being touted as positive for brain health. Confounding variables like sleep, trauma history, socioeconomic status, and physical activity can complicate research results. Additionally, the wellness space often overhypes findings prematurely, presenting nutrition as a “cure” for psychiatric conditions when the reality is far more complex. This becomes especially problematic when applying nutritional psychiatry concepts to eating disorder treatment. The concern isn’t education itself- it’s when information about “brain-healthy” foods is used to restrict, moralize eating, or override hunger and satisfaction cues.

At New Paths Nutrition, our philosophy is always adequacy first in dietary intake. Rachael Hartley’s Hierarchy of Needs illustrates this well: we cannot take a “food as medicine” approach when intake is inadequate. Everyone starts a different baseline, depending on their access to food and severity of eating disorder. You can eat all the raw kale and quinoa you want, but if you aren’t getting enough protein and carbohydrates, your body (and brain!) will feel the difference. I often tell clients to think of vitamins and minerals like contract workers: they can only do their jobs when the business is running smoothly, and there’s enough cash flow. As a dietitian, I can appreciate the desire to optimize nutrition, and as an eating disorder dietitian, I know that optimizing doesn’t always equate to healing, especially when basic needs aren’t being met. When clients are eating enough consistently, nutrition education can become supportive instead of stressful.

To illustrate this, I'll outline some case examples.

Take Jane, for example. Jane has been diagnosed with OSFED per the DSM-5, and her presentation is known as orthorexia. Orthorexia is not officially in the DSM-5 on its own because it falls under the “other” umbrella (aka OSFED). It typically involves an obsession with eating in a “whole” or “correct” way all of the time. You can read more about it in our blog post here. Jane relies on calorie counting, weighing her food, and reading labels excessively to manage her food anxiety. Most of her diet would be considered “clean” by wellness culture standards, and she never deviates from these standards. She wishes she could go to drinks and tapas with friends without extreme panic. Jane is tired, her hair is falling out, and she has low iron. Her dietitian and therapist are encouraging her to work on her distress tolerance around fear foods and social eating so she can return to her “normal” life. 

Now, Betty:

Betty has been diagnosed with Binge Eating Disorder (BED). She spends most of her day trying to “be good,” often skipping breakfast and eating only a salad for lunch. By the time evening hits, she feels ravenous and out of control around food. Betty often binges alone at night, followed by intense shame and promises to herself that she’ll “start fresh tomorrow.” She avoids social events that involve food because she’s scared someone will notice how much she eats. Betty also experiences significant swings in energy, chronic GI discomfort, and emotional exhaustion from constantly feeling like she’s failing at willpower. Her dietitian and therapist are helping her rebuild consistent, adequate meals throughout the day and unpack the diet-culture beliefs driving her restrict–binge cycle. Betty’s goals include feeling peaceful at dinner with her partner and trusting her body’s cues again.

And lastly, Ethan:

Ethan has been diagnosed with ARFID, specifically the sensory sensitive subtype. Since childhood, certain textures and smells have triggered intense avoidance. He can tolerate a handful of foods like crackers, plain pasta, and a few specific brands of chicken nuggets. As he’s gotten older, his limited intake has started to affect his growth, concentration, and energy levels. Ethan wishes he could join his coworkers for lunch or go on dates without panicking about what will be served. He’s embarrassed that people think he’s “picky,” when in reality, eating unfamiliar foods triggers a full stress response. His care team is supporting him with gradual exposure work, nervous system regulation, and expanding his tolerated foods without shame. His long-term hope is to eat a wider range of meals so he can participate more fully in his social life and meet his body’s nutritional needs.

These case studies are anecdotal of common client presentations where I could not ethically use the “nutritional psychiatry” approach as our only/primary focus. A huge misconception with eating disorder nutrition is the notion that we are only “pushing” processed foods in recovery. As trauma-informed, critical-thinking dietitians, we work with each client on a case-by-case basis to give them the most individualized, empathetic care possible. Our job as dietitians is to incorporate the science of nutrition AND our client’s unique situation. And like these case studies above, some clients may need to challenge their processed food fears to improve their quality of life.

We can absolutely use a nutritional psychiatry approach with a client while still honoring their history of disordered eating. The key is how and when they’re introduced. Sometimes clients may not be in a place where focusing on specific nutrients would be safe or supportive. When clients are eating enough, working toward flexibility, and no longer using food rules to manage anxiety, learning about the mental health benefits of food can feel supportive and even healing.

As eating disorder dietitians, our role is to make sure this information never becomes another way to chase “perfect” eating and restrict food. If education starts to fuel rigidity, fear, or obsession, we pause and return to the foundations of recovery: adequacy, consistency, and trust.

So what does the research say?

Research in nutritional psychiatry suggests that nutrition can support mental health, especially for individuals without active eating disorder symptoms and when basic nutrition needs are met. Studies highlight key nutrients and foods linked to brain function and mood regulation:

• Omega-3 fatty acids (DHA and EPA) support cognition and memory, reducing inflammation and improving cognitive performance (Dighriri et al., 2022).

• Antioxidant- and polyphenol-rich foods like berries may enhance memory and executive functioning (De Amicis et al., 2022).

• Turmeric and curcumin have neuroprotective effects by reducing oxidative stress (Abass et al., 2020).

Diets rich in omega-3s, B vitamins, magnesium, zinc, iron, and phytonutrients help regulate mood, focus, and inflammation, while fiber-rich and fermented foods support the gut-brain axis. For depression specifically, omega-3 and vitamin D supplements show some strong evidence of benefit (Dighriri et al., 2022).

These findings support nutritional psychiatry’s focus on nutrient-dense foods that provide essential vitamins, minerals, antioxidants, and healthy fats to optimize brain function. However, there are few randomized controlled trials focused specifically on eating disorder outcomes using nutritional psychiatry. More research is necessary to explore causal links and study more populations, including those with eating disorders.

Importantly, this doesn’t mean clients need to eat “perfectly” or follow a rigid diet to support mental health. Consistent, adequate nourishment matters far more than individual “superfoods.” These findings highlight patterns and associations (not strict rules!) and do not replace the need for individualized, compassionate care.

For more information on foods linked to better brain health, see: https://www.health.harvard.edu/healthbeat/foods-linked-to-better-brainpower

In conclusion, emerging research in nutritional psychiatry highlights the significant relationship between nutrition and mental health. At New Paths Nutrition, we incorporate these scientific principles, all while reinforcing the importance of a stable, compassionate relationship with food. Prioritizing adequate, consistent nourishment, food access, and flexibility is essential before focusing on specific nutrients or dietary patterns. A weight-inclusive, non-diet framework allows nutrition to support mental well-being without reinforcing restriction, fear, or “magic-bullet” thinking. Ultimately, nutrition can be a supportive tool for mental health, but it is most effective when integrated thoughtfully alongside therapy, medication when indicated, and individualized, multidisciplinary care. When handled with care, and when clients are ready, nutrition education can help clients feel more connected to their bodies-not more afraid of food.

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Sources:

Abass, S., Latif, M., Shafie, N., Ghazali, M. I., & Kormin, F. (2020). Neuroprotective expression of turmeric and curcumin. Food Research, 4(6), 2366–2381.

Cassidy, J., MS, RD, CIEC, & CEDS-C. (2025). Does what you eat impact mental health? A dietitian explains. Eating Recovery Center. https://www.eatingrecoverycenter.com/resources/nutritional-psychiatry-mental-health

De Amicis, R., Mambrini, S. P., Pellizzari, M., Foppiani, A., Bertoli, S., Battezzati, A., & Leone, A. (2022). Systematic review on the potential effect of berry intake in the cognitive functions of healthy people. Nutrients, 14(14), 2977. https://doi.org/10.3390/nu14142977

Dighriri, I. M., Alsubaie, A. M., Hakami, F. M., Hamithi, D. M., Alshekh, M. M., Khobrani, F. A., … Tawhari, M. (2022). Effects of omega-3 polyunsaturated fatty acids on brain functions: A systematic review. Cureus, 14(10).

Grosso, G. (2021). Nutritional psychiatry: How diet affects brain through gut microbiota. Nutrients.

Hartley, R. (2020). The hierarchy of nutrition needs: A non-diet approach to understanding nutrition. Rachael Hartley Nutrition. https://www.rachaelhartleynutrition.com/blog/the-nutrition-hierarchy-of-needs

Lin, J. A., Stamoulis, C., & DiVasta, A. D. (2023). Associations between nutritional intake, stress and hunger biomarkers, and anxiety and depression during the treatment of anorexia nervosa in adolescents and young adults. Eating Behaviors, 51, 101822. https://doi.org/10.1016/j.eatbeh.2023.101822

Physician’s Committee for Responsible Medicine. (n.d.). Eating disorders. In Nutrition Guide for Clinicians. https://nutritionguide.pcrm.org/nutritionguide/view/Nutrition_Guide_for_Clinicians/1342074/all/Eating_Disorders

Produce for Better Health Foundation. (n.d.). What are phytochemicals? Fruits & Veggies — Have A Plant. https://fruitsandveggies.org/blog/what-are-phytochemicals/

Selhub, E. (2022). Nutritional psychiatry: Your brain on food. Harvard Health Publishing. https://www.health.harvard.edu/blog/nutritional-psychiatry-your-brain-on-food-201511168626